CVE-2025-34491

Name: CVE-2025-34491
Creator: NVD / NIST
Published: 2025-04-28T20:15:20.997+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.71%

Last modified Jun 17, 2026

CVE-2025-34491 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup.. EPSS estimates a 0.71% chance of exploitation in the next 30 days.

Description

GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.71%

49.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gfi	Mailessentials	< 21.8

References

Timeline

Published: Apr 28, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-34491?

How severe is CVE-2025-34491?

CVE-2025-34491 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.

How do I fix CVE-2025-34491?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-34491?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST